Road roller



F. E. STECK ROAD ROLLER July 30, 1968 Filed March 25. 1967 INVENTOR 1lixJmmuc/ 15m: ick

United States Patent 3,394,641 ROAD ROLLER Ferdinand Edgar Steck, Bowil,Switzerland Filed Mar. 3, 1967, Ser. No. 620,518 Claims priority,application Switzerland, Mar. 18, 1966, 3,924/66 5 Claims. (Cl. 94-50)ABSTRACT OF THE DISCLOSURE A road roller of the type in which both thefront and rear rollers are driven and wherein the support means for thefront roller is pivotable about a vertical axis with respect to thesupport means for the rear roller, such pivotable movement preferablybeing carried out through the agency of a suitable steering or guidemechanism. A suitable drive motor provides drive means for the front andrear rollers According to one aspect of the invention a drive connectionis incorporated between such front and rear rollers and includes a bevelgear drive. Such bevel gear drive embodies at least two bevel gearswhich are pivotably mounted for movement relative to one another aboutthe aforementioned vertical axis even under load, and wherein suchvertical axis at least approximately coincides with a common tangenttaken through both of the pitch circles of said bevel gears.

Background of the invention The present invention has reference to animproved road roller of the type wherein both the front as well as alsothe rear roller are driven, and furthermore, wherein the bearing supportfor the front roller is pivotable relative to the bearing support of therear roller about a vertical axis by means of a suitable steeringmechanism.

Road rollers of the above-mentioned general type are already known tothe art. In prior art constructions of such type road rollers theimportant advantage of the steerability of the front roller is onlyobtained with an exceptionally great constructional expenditure. Moreprecisely, to achieve such maneuverability or steerability there isprovided, among other things, in the drive connection between the frontand rear rollers a transmission shaft which is rotatable about thesteering axis and in order to support such shaft there is furtherprovided a housing which is fixedly connected with the bearing supportof one of these two rollers and rotatably connected for movement aboutthe steering axis with the bearing support of the other of these tworollers. A further drawback resides in the fact that the turning ordeflection, particularly during standstill, results in considerablyloading the members of the drive connection because such a turning ordeflection results in a rotation about the vertical transmission shaft,that is to say, an additional rotation of one of both rollers.

Summary of the invention Accordingly, it is a primary object of thepresent invention to provide an improved construction of road rollerwhich overcomes the aforementioned drawbacks of the prior artstructures.

Another, more specific object of the present invention pertains to animproved construction of road roller allowing for positivemaneuverability of such road roller with a minimum structuralexpenditure.

Yet a further significant object of this invention pertains to animproved road roller possessing drive connection means between thedriven front and rear rollers thereof and which provide a relativelysimple, inexpensive yet highly reliable construction insuring for therequired maneuverability of such road roller.

Now, in order to implement these and still further objects of theinvention which will become more readily apparent as the descriptionproceeds, the invention contemplates that the drive connection betweenthe forward roller and the rear roller and a drive motor for both suchrollers possesses a bevel gear drive. This bevel gear drive has twobevel gears which are pivotable relative to one another about theaforementioned vertical axis even under load, and which vertical axis atleast approximately coincides with a common tangent taken through bothof the pitch circles of said bevel gears.

According to a preferred manifestation of the present invention one ofthe bevel gears which are pivotable with respect to one another isseated upon a connection shaft which extends within the bearing supportof the front roller substantially parallel to the latter. Further, theother bevel gear is seated upon a transmission shaft which extends inthe lengthwise direction of the road roller approximately in the middlethereof. This transmission shaft is mounted at a portion of the bearingsupport of the rear roller and upon which also a bearing housing isaxially non-displaceably mounted for rotation about the axis of rotationof such transmission shaft. The bearing support for the front roller ismounted beneath and above the bevel gear drive at the bearing housingfor pivotal movement about the aforementioned vertical axis.

Owing to this construction there is achieved that both of the rollerscan readily accommodate themselves to irregularities in the slope of thestreet, road or the like.

Brief description of the drawing The invention will be betterunderstood, and objects other than those set forth above, will becomeapparent, when consideration is given to the following detaileddescription thereof. Such description makes reference to the annexeddrawing wherein:

FIGURE 1 is an elevational view, partially in longitudinal section, of apreferred embodiment of inventive road roller;

FIGURE 2 is a horizontal cross-sectional view of the road roller ofFIGURE 1, taken along the line 11-11 thereof; and

FIGURE 3 is an enlarged view showing a detail of the road roller ofFIGURE 2, and specifically both of the bevel gears which are pivotablewith respect to one another about a vertical axis.

Description of the preferred embodiment Describing now the drawing,reference numerals 1 and 2 respectively designate the front and the rearroller of the inventive road roller device. The vibrators which areusually mounted in such rollers 1, 2 have been conveniently omitted fromthe drawing since they do not form subject matter which is part of thepresent invention, nor are any details thereof necessary forunderstanding the principles of the invention. Continuing, the frontroller 1 is mounted at a bearing support means 3. This bearing supportmeans 3 is mounted at its rear end, which is disposed approximately inthe middle of the road roller, at the 10- cations 4 and 5 about avertical axis AA at the forwardly directed eyelets or lug portions 6a ofa bearing housing or body 6. Bearing housing 6 is of essentiallysleeve-like configuration and is rotatably mounted, yet axiallynon-displaceable, upon a forwardly depending cylindrical shoulderportion 7a of a main bearing support means 7. The rear roller 2 ismounted at this bearing support means 7 and an overhang arm or bracket7b is provided thereat upon which there is mounted a suitable drivemotor 8.

Drive motor 8 drives a gear 11 through the agency of a multiple V-beltdrive 9 or another suitable drive, and further, through the intermediaryof a gear train or reduction gearing 10. Gear 11 is fixedly seated upona transmission shaft 12 mounted in the main bearing support means 7 infront of the rear roller 2. A chain or sprocket gear 13 and a bevel gear14 are also fixedly seated upon this transmission shaft 12. Startingfrom the sprocket gear 13 the drive or motive power is transmitted bymeans of a chain 15 to a sprocket wheel or gear 16 which is rigidlyconnected for rotation with the rear roller 2.

The bevel gear 14 meshes with a bevel gear 17 which is fixedly mountedat a transmission shaft 18. This transmission shaft 18 is rotatablymounted in the main bearing support means 7 for rotation about an axiswhich coincides with the axis of the rotatable bearing of the bearinghousing 6 seated on the shoulder 7a of the main bearing support means 7.The drive connection from the drive motor 8 and from the rear roller 2to the front roller 1, in addition to the already mentioned chain drive13, 15, 16, the transmission shafts 12, 18 and the pair of bevel gears14, 17, also further incorporates two continuously meshing bevel gears19 and 20, a transmission or connection shaft 21 rotatably mounted inthe bearing support means 3 in a direction substantially parallel to theaxis of the front roller 1, and further a chain drive 2-2, 23 and 24which corresponds to the previously considered chain drive 13, 15 and16. The teeth of both of the bevel gears 19 and possess the formdepicted in FIGURE 3. Their pitch circles have a common tangent which atleast approximately coincides with the vertical axis A-A about which ispivotably mounted the bearing support means 3 at the bearing housing 6.

Pivoting of the bearing support means 3 about the above-mentioned axisAA, and for the purpose of steering the front roller 1, can take placeeven if the gears 19 and 20 are under load, that is to say, during suchtime as the road roller is working or otherwise operated. Such pivotingof the bearing support means 3 advantageously takes place by means of asuitable steering or guide mechanism which may incorporate a hydraulicpiston and cylinder arrangement 25, the rear end of which is hingedlyconnected to a lateral overhang arm or bracket 6b of the bearing housing6 and the front end of which is hingedly connected to the bearingsupport means 3. This piston and cylinder arrangement 25 isdouble-acting and is operably connected to a conventional controlcircuit also having a standard control mechanism which can beconveniently operated by an operator riding upon the road roller andsitting upon a non-illustrated seat arranged approximately adjacent theoverhang arm or beam 7b.

With such a turning or deflection of the support means 3 for the frontroller 1 the latter for instance assumes the position shown in phantomlines in FIGURE 2. Irrespective of whether such a turning has takenplace or not, the entire forward portion, which includes the frontroller 1, its bearing support means 3 and the bearing housing 6, canfreely rotate about the cylindrical shoulder 7a, in order that thisfront roller 1 can accommodate itself independently of the rear roller 2to differences in the slope of the street, road or the like upon whichthe road roller is being propelled or upon which road work is beingundertaken.

Naturally, different modifications can be undertaken with regard to thedescribed and exemplary depicted embodiment, without departing from thespirit and scope of the inventive concepts. For instance, it would bepossible to do without the seat and without the mentioned steering orguide mechanism which includes the hydraulic arrangement 25, yet howeverthe one or the other of the support means 3 and 7 would be provided witha wagon shaft or center pole which would be operated or guided by theattendant walking behind the road roller.

While there is shown and described a present preferred embodiment of theinvention it is to be distinctly understood that the invention is notlimited thereto but may be otherwise variously embodied and practicedwithin the scope of the following claims, Accordingly,

What is claimed is:'

1. A road roller comprising:

a pair of driven rollers, one of which defines a front roller and theother a rear roller;

first support means for rotatably mounting said front roller;

second support means for rotatably mounting said rear roller;

means for mounting said first support means provided for said frontroller for pivotal movement about a substantially vertical axis andrelative to said second support means;

drive means for driving both said front and rear rollers;

drive connection means cooperating with said drive means and interposedbetween said front and rear rollers;

said drive connection means incorporating a bevel gear drive having atleast two bevel gears which are pivotably mounted for movement relativeto one another about said vertical axis even under load, said verticalaxis at least approximately coinciding with a common tangent takenthrough both of the pitch circles of said bevel gears.

2. A road roller as defined in claim 1, wherein said drive meansincludes drive motor means.

3. A road roller as defined in claim 1, wherein said drive connectionmeans further includes a connection shaft upon which is mounted one ofsaid relatively pivotably mounted bevel gears, said connection shaftextending within said first support means for said front roller in adirection substantially parallel to the latter, a transmission shaftupon which is mounted the other bevel gear, said transmission shaftextending in substantially lengthwise direction of the road roller andapproximately in the middle thereof, said second support means for saidrear roller including a support portion at which is mounted saidtransmission shaft, a bearing housing mounted for rotation about theaxis of rotation of said transmission shaft and axially non-displaceableupon said support portion, said bearing housing providing said mountingmeans at which said first support means for said front roller is mountedbeneath and above said bevel gear drive for pivotal movement about saidvertical axis.

4. A road roller as defined in claim 3, further including steering meansfor bringing about pivotal movement of said first support means for saidfront roller about said vertical axis.

5. A road roller is defined in claim 4, wherein said steering meanscomprises a double-acting piston and cylinder arrangement having one endpivotably connected with said bearing housing and the other endpivotably connected with said first support means for said front roller.

References Cited UNITED STATES PATENTS 2,132,107 10/1938 'Hamm 945O2,691,927 10/1954- Denton 94-50 X 2,728,277 12/1955 McRae 9450 3,228,312l/l966 Neidhardt 94-5O 3,326,312 6/1967 Buller 945O 3,339,468 9/1967Hall 9450 NILE C. BYERS, 111., Primary Examiner.

